New Delhi: Claiming that it found several antibiotic residues in chickens tested in Delhi-NCR region, an environment body Wednesday said "large-scale and indiscriminate" use of antibiotics in poultry industry might be "strongly linked" to growing antibiotic resistance in Indians.

The Centre for Science and Environment (CSE) also sought implementation of a comprehensive set of regulations including banning of antibiotic use as growth promoters in the poultry industry as it puts lives of people at risk.

It said that 70 chicken samples from Delhi-NCR region were tested for six commonly used antibiotics during a recent study. While 40 per cent tested positive, residues of more than one antibiotic were found in 17 per cent samples.

"Indians are developing resistance to antibiotics and hence falling prey to a host of otherwise curable ailments. Some of this resistance might be due to large-scale unregulated use of antibiotics in the poultry industry," CSE said.

The New Delhi-based research and advocacy think-tank said that antibiotics which are important to treat diseases in humans, like ciprofloxacin, are being rampantly used by the industry. This is leading to increased cases of antibiotic resistance in India.

"Antibiotics are no more restricted to humans nor limited to treating diseases. The poultry industry uses antibiotics as a growth promoter. Chickens are fed antibiotics so that they gain weight and grow faster," said Sunita Narain, Director General while releasing the study conducted by CSE's Pollution Monitoring Laboratory (PML).

The CSE said that India has no regulation on controlling antibiotic use in the poultry industry or to control sales of antibiotics to the industry while it has not set any limits for antibiotic residues in chicken.

Giving details, CSE said that PML tested 70 samples of chicken in Delhi and NCR out of which 36 samples were picked from Delhi, 12 from Noida, eight from Gurgaon and seven each from Faridabad and Ghaziabad.

Three tissues muscle, liver and kidney were tested for the presence of six antibiotics widely used in poultry - oxytetracycline, chlortetracycline and doxycycline (class tetracyclines), enrofloxacin and ciprofloxacin (class fluoroquinolones) and neomycin, an aminoglycoside.

"Residues of five of the six antibiotics were found in all the three tissues of the chicken samples. They were in the range of 3.37-131.75 g/kg. Of the 40 per cent samples found tainted with antibiotic residues, 22.9 per cent contained residues of only one antibiotic while the remaining 17.1 per cent samples had residues of more than one antibiotic, the study said.

"Public health experts have long suspected that such rampant use of antibiotics in animals could be a reason for increasing antibiotic resistance in India," said Chandra Bhushan, CSE's deputy director general.

"But the government has no data on the use of antibiotics in the country, let alone on the prevalence of antibiotic resistance. Our study proves the rampant use and also shows that this can be strongly linked to growing antibiotic resistance in humans in India," he added.

Explaining the fallout of this, CSE officials said that large-scale misuse and overuse of antibiotics in poultry industry is leading to the emergence of antibiotic-resistant bacteria in the chicken itself.

These bacteria are then transmitted to humans through food or environment. Additionally, eating small doses of antibiotics through chicken can also lead to development of antibiotic-resistant bacteria in humans, the study said.

It said that in India, there is growing evidence that resistance to fluoroquinolones such as ciprofloxacin is rapidly increasing.

Treating fatal diseases like sepsis, pneumonia and tuberculosis (TB) with fluoroquinolones is becoming tough because microbes that cause these diseases are increasingly becoming resistant to fluoroquinolones, the study said.

CSE researchers point out that antibiotics are frequently pumped into chicken during its life cycle of 35-42 days. They are occasionally given as a drug to treat infections regularly mixed with feed to promote growth and routinely administered to all birds for several days to prevent infections.

"Our study is only the tip of the iceberg. There are many more antibiotics that are rampantly used that the lab has not tested," Bhushan said.

The CSE also recommended banning the use of antibiotics as growth promoters and for mass disease prevention, not allowing antibiotics critical for humans in poultry industry, not using antibiotics as a feed additive, regulation of poultry feed industry by the government and not selling unlicensed and unlabelled antibiotics in market among others.